Octa's transportation blog

Keeping Up with Progress on the I-405

The largest project in OCTA’s history, the I-405 Improvement Project, is on schedule to meet key construction milestones and open the 405 Express Lanes in late 2023. In addition to improving a 16-mile stretch of the freeway between Costa Mesa and the Orange County border with Los Angeles County, the project is adding one regular lane in each direction between Euclid Street to I-605, and a second lane in each direction in the center of the freeway from SR-73 to I-605 that will combine with the existing carpool lanes to form the 405 Express Lanes.

Highlights include:

  • Recently passing the 75% completion mark
  • By the end of the summer, 12 of 18 bridge replacements are expected to be complete
  • Nearly 85% of walls are complete, 75% of ramp reconstruction is complete and 65% of the paving operations is complete
  • 45 of the 58 ramps are now complete.

During the summer, OCTA will continue to keep the stakeholders, residents and business owners throughout the project corridor informed.

Please note that there will be an I-405 full freeway closure in Costa Mesa 8:00 p.m. June 4 to 11:00 a.m. June 5. For more information on detours, please visit the project website.